Calculating machine



Oct. 12, 1937.

G S s a am@ @wg R. L. MULLER CALCUIJA'IING MACHINE Filed Oct. 19, 1933 5 Sheets-Sheet l INVENTOR Oct. 12, 1937. R. L. .MULLER CALCULATING MACHINE Filed Oct. 19, 1933 5 Sheets-Sheet 2 lNvENToR Paie/ L. fwd/6l" l 'ATTORNEYS Oct. 1.2, 1937. R. L. MULLER CALCULATING MACHINE Filed Oct. 19, 1933 5 Sheets-Sheet 3 ATTORNEYS Oct. 12, 1937. R. Ll MULLER .GALCULATING MAHINE Filed Oct. 19, 1933 5 Sheets-Sheet 4 7 NVENTOR EDU M40", y ma?,

ATTORNEYS v Patented Oct. 12, 1937 UNITED -sTATEs PATENT OFFICE CALCULATING MACHINE Application October 19, 1933, Serial No. 694,230

9 Claims.

This invention relates to calculating machines, more particularly to a multiple register machine and concerns the register controlling mechanism therefor.

The present demand is for calculating machines capable of simultaneously performing a plurality of calculating operations. This requirement necessitates either a multiplicity of registers or suitable controls fortwo or more registers whereby amounts may be entered simultaneously into the registers independently of each other and regardless of the character of the entry, and means for totaling the registers regardless of the condition of the registers and character of the totals.

In posting bank account transactions, for example, it -is desirable to enter the deposits or addition amounts in one column, the withdrawal or subtraction amounts in another column, and the daily balances mixed or otherwise in a third column. Forspeed and efficiency, it is also desirv able to be able to post a. plurality of accounts were not independent.

tion and arrangement made it possible to simultaneously enter two amounts, one in each of the register sections and if the register sections were each constructed for addition and subtraction, either type of entry could be made.

In sucha machine totals could be taken at any desired time in either 'of the register sections provided that both register sections were in the same condition, that is, provided both were positive or both negative. If the balance was mixed, that is, if one section was in positive condition and the other in negative condition, one total only could be taken because the two register sections It is obvious that such a machine has certain limitations in that mixed balances cannot be taken if desired. Therefore,

the machine cannot be used `to print both posi- .tive and true negative totals.

It is, therefore, within the contemplation of this invention to increase the flexibility of the machine by increasing the possible uses with a. limited number of registers thereby having the .effect of increasing the number of registers Without, however, any consequent complicity of register control.

The general object of this invention is to provide an improved register controlling mechanism for a multiple register machine.

A more particular object is to provide an irnproved register controlling mechanism for multiple register calculating machines which will permit the simultaneous entry of amounts in the several registers and the taking of totals therefrom regardless of thecondition of the register, that is, whether it contains a positive or negative total,

Other objects and advantages of the invention will appear from the specification and drawings which illustrate one embodiment of the invention and in which,

Figure 1 is a left side sectional elevation of a calculating machine embodying the present invention with parts removed, the register controls being in normal position;

Fig, 2 is a perspective View from the front left corner of the machine showing the register control devices and associated mechanism for each register or section of registers with both sections in normal or positive condition;

Fig. 3 is an enlarged View of the center portion of Fig. 2;

Fig. 4 is a partial left side elevation taken in different planes showing the register controls in position after a negative balance has occurred in one section of the machine and the carriage having moved to the balance column and with the total key locked against depression as a warning to the operator of the machine;

Fig. 5 is also a partial left side elevation showing the register controls, and total key in positionafter a negative balance has occurred in one section and after the total key lock has been removed by manual operation and with the total l. key depressed for the first totaling operation of the mixed balance posting;

Fig. 6 is a fragmentary detail of the register control mechanism on the right side of the machine; and

Fig. 7 is a sample form in which two different mixed balance postings are illustrated. D

The illustrated embodiment of this invention for accomplishing the heretofore-mentioned desired end is shown as applied to a Burroughs bookkeeping or posting machine such as that shown and described in the patent issued to Pasinski No. 1,778,506, although it will be obvious to those skilled in the art that the invention may be applied equally well to other types of calculating machines.

Calculating machine generally As previously stated, the machine is a typical Burroughs bookkeeping or posting machine having a keyboard with depressible keys I which engage cranks 2 to which control Wires 3 are attached which latter Wires under the control of the keys limit the movement of actuator racks 4 and 4a carried upon the forward ends of levers 6, pivoted at '|.v Levers 6 carry type bars 8 upon their rear ends which are struck by hammers 9. The actuator racks 4 and 4a engage add and subtract registers of the tumbling type vcomprising adding wheels I and IIJ and cooperating subtracting wheels II and IIEl carried by a supporting frame I2. The registers may be placed in either addition or subtraction position by a manually operable lever I3 which causes the register to be tumbled intoeither add or subtract condition in the usual manner. The illustrated machine being of the duplex type it also has a third register I4 (Fig. 1).

The keys, racks, printing mechanisms, and registers are divided into sections, two lsections vonly being shown in this machine for the purpose of simplicity although it is obvious that more sections may be employed. This division makes it possible to simultaneously enter independent amounts in each section by depressing suitable keys in each section of the keyboard. The register sections are designated I0 and Ille for the addition wheels and I I and I I=1I for the subtraction wheels (Fig. 2), Wheels I0 and II being for the left section of the register and wheels Illa and |I a being for the right section of the register.

Since the entire register is carried and operated in a single frame I2, when one section of the machine is in condition for addition, the adjoining section of the machine is likewise in condition for addition, the same relation being true when the register frame is changed to subtract position.

f However, the amounts set up on the keybpard in K ous columns.

` tions.

each section areindependently controlled by the keys of each section and accordingly the amounts contained in the separatesections may vary to any desired degree evento the extent of causing an overdraft or negative balance in one section carriage 20 which supports a platen 2| and is-slidable horizontally and may be tabulated into vari- Furthermore, the carriage is providedwith the well-known mechanism for automatically conditioning the machine foreither addition or subtraction in selected columnar posi- For example, the machine illustrated is adjusted to condition the machine for addition in column 1, subtraction in column 2, and totaling in column 3, the balances in the latter column being either positive or negativey amounts depending upon the condition of the registers. Each column is of sufficient width to permit two entries therein. Accordingly, it will be noted (Fig. 7) that each column contains two columns of figures for two different accounts or series of items. Entries in the two accounts may-be enterd simultaneoushand crank or by means of a motor (not shown). During the forward stroke of the machine, the

. registers are disengaged from the racks 4 and 4a,

which racks are allowed to descend until limited against the index wires 3, which have been set by depression of the keys., After the racks have descended to their limits, hammers 9 drive type bars 8 against the platen 2| to print the amount on the paper forms carried by the paperA carriage. During the return stroke of the machine, the registers are engaged with the actuator racks 4 and 4gand during return of the racks to normal position the register wheels are rotated by the racks'.

Assuming that the machine is in normal condition for addition, the addition wheels IIJ and Il)B are engaged with racks 4 and 4a and are rotated clockwise as viewed in Fig. 1 upon return of the actuator racks 4 and 4a. The subtraction wheels I I and I Ia being in engagement with the addition wheels I0 and Illa, are, of course, rotated counterclockwise. If the machine is setin condition for subtraction by operationA of lever I3, the subtract wheels II and IIa will be engaged with the actuator racks 4 and will be rotated clockwise thus rotating the addition wheels I0 and Illa in a counterclockwise direction during the return of the racks to normal position.

When a carry or transfer occurs during the adding or subtracting operation, the usual cam 24 or 2lia on either the add or subtract wheels I0, II, II)a or IIa advances the wheel of the next higher order at the completion of the machine operation.A

The usual total key T is provided and when depressed conditions the controls to engage registers" with the racks during the forward stroke of the machine. No keys having been depressed, the racks are limited by the register pinions uponI reaching zero instead of being limited by the index wires 3 which are not actuated.

If a smaller amount has been subtracted from a larger amount in one sectionof the register, the balance is positive and is taken from the addition register wheels I0. On the other hand,

if a larger amount is subtracted from a'slnaller amount, in a given register, the balance is negative and the register must be tumbled until the subtraction wheels I I are engaged with the actuator racks 4 after which a total is taken by zeroizing the subtract wheels II. In the illustrated machine, there is no indication of which register is in negative condition, however, means are provided for locking the total key whenever either or both of the registers is in negative condition.

Negative total locks Each section of the machine is provided with a negative total lock which mechanisms are indicated generally at A and B (Fig. 2), A indicatl I0 (Fig. 2) and a second lever 28 pivoted at 29 and terminating in a foot 3| in position to be engaged by cam 24 of the highest order of the subtract pinions II. 'I'he upper end of lever 28 is in position to engage a stud 32 carried by one arm of a three-armed lever 33 pivoted at 34, the second arm of which terminates in a spear point 36 engageable with a detent 31. Normally when the machine is in positive condition the spear point 36 lies to the rear of detent 31 (Figs. 1 and 2) whereas, when the negative total mechanism has been actuated, spear point 36 lies forward of detent 31 (Figs. 4 and 6) because of the counterclockwise position assumed by lever 33 in Fig. 4, and clockwise in Fig. 6.

When the register goes negative, however, as when an overdraft occurs, cam 24 of the highest order of the subtraction pinion II engages the foot 3I and swings lever 28 clockwise about its pivot causing the upper end of lever 28 to move stud 32 and rotate three-armed lever 33 counterclockwise, in Fig. 4, and clockwise in Fig. 6, thus moving stud 38 carried by the upper end of the third arm of lever 33 out of the forward notch 39 of link 4I as shown in Fig. 4, raising link 4I slightly. 'Ihe upper edge of link 4I underlies and engages a stud 42 carried by one arm of a bail 43 pivoted on the cross shaft 44 extending across the machine. Adjacent the left end, bail 43 is provided with a downwardly depending arm 46 which is yieldingly connected by spring 41 at its lower end to a pendant 48 (Fig. 4). When the negative total lock is operative, pendant 48 engages a stud 49 carried by a forwardly extending arm I of a lever 52 urged clockwise by a spring 55 which also has an upwardly extending arm 53 underlying a stud 54 carried by the total key. Accordingly when a negative total occurs in the left register section, the cam 24 will engage lever 28 and through the mechanism just described cause lever 52 to be rocked counterclockwise to present its arm 53 immediately below stud 54 to prevent depression of the total key, thus notifying the operator that a negative total occurs in one of the registers. The negative total lock mechanism thus far described is similar to that illustrated and described in the previously mentioned Pasinski patent to which reference is made for further details.

The negative vtotal lock mechanism for the right section is similar to that for the left section shaft 44, being divided into two coaxial sections 44 and 44a (Fig. 2). The ball 43a for the right section corresponding to 43 for the left hand section extends to the left end of shaft 44 where it terminates in a depending arm 46* yieldingly connected by a spring 41a to a pendant 48, the pendant 482 being engageable with stud 48 which projectsfrom both sides of the extension 5I of the arm 52 as shown in Fig. 2. Because of the foregoing mechanism the total key will be locked when either register is in negative condition or when either section contains a total contrary in sign to the current position of the add subtract lever. 'Ihe operator, therefore, knows that one or both 0f the registers are in negative condition and the total key must be released before a totaling operation can be performed. If both register sections are in positive condition, and frame I2 is in -add position the negative total locks are, of course, inoperative and a total of both registers may be taken simultaneously and immediately. 'I'he same is true if both sections and the frame I2 are in negative position provided the total keys are rst released.

Negative total lock release A1f eitherone or both of the register sections is in negative'condition, the total key is blocked against depression and must be released prior to taking a total. A manuallyoperable lever 68 is provided for releasing the negative total block. The lever 60 is pivoted freely on shaft 44 and is formed with a depending arm 6I (Fig. 4) engageable with both pendants 48 and 48' to rock them away from the stud 48 to return lever 52 to nonlocking position, i. e., to disable or normalize lblocking lever 52 after which the total key may be depressed for taking the first of the totaling operations. Springs 41 and 41 provide a yielding connection between arm 46 and pendant 48 and between arm 46a and pendant 48, respectively, and permit movement of lever 68 although balls 43 and/or 43a are held in clockwise and overdraft position by the negative total lock mechanism, i. e., the yielding connections permit movement of pendant 48'i although arm 46* may be blocked and vice versa.

In the machine which has been chosen for illustratingl one example of a practical embodiment of the invention, the register frame is not moved from its adding position to its subtracting position and vice versa directly upon the movement of the add subtract lever I3 from one position to the other but the register frame I2 is moved from the adding position to the subtracting position and reversely during and by the operation of the machine following a change in the position of the lever I3. locking means (not illustrated) constructed as shown in the previously mentioned Pasinski patent, for locking the total key against depression for a total taking operation, in which the register must be engaged with the actuator racks during the forward stroke of operation, when the register frame is not in the position corresponding to the setting of the add subtract lever and must therefore be moved from the one to the other position during the operation of the machine. 'I'hat is, whenever the position of the add subtract lever and the position of the register frame do not agree depression of the total lever is prevented. To release the total key if it is blocked by this locking means after the add subtract -lever has been shifted to a position corresponding to the kind of total to be taken it is necessary to give the machine a spacing operation by rwhich the register frame is moved to the position corresponding to the new position of the add subtract means.

Mixed balance posting The mechanism thus far described is not sufficient for taking totals when a mixed balance The machine is provided with a is in the machine, that is when one section of the register contains a positive total and the other section contains a negative total. In order to take such totals provision must be made for clearing or zeroizing the register or sections having totals of one sign during the first totalizing operation while preventing the other section or sections, if the register has more than two sections, from zeroizing. In other words provision must be made for independently taking a total from one section without affecting the other section and then taking a total of the remaining section or sections without affecting the first section which has been cleared because of the first totaling operation.

Accordingly this invention provides means for first, totaling and zeroizing one or more sections independently of the other section or sections, i. e., while preventing clearing of the other section and second, for enforcing manual operation of the control lever to subtract positionii.` one register section is in overdraft condition to take the true negative total of such section while maintaining the other register section cleared. In order that a true negative total may be drawn from either section of the register, each section of the register is preferably provided with a fugitive 1 mechanism, which is not illustrated but which is of a known type, such, for example, as that discussed in the Pasinski Patent No. 1,788,- 506 and as described and illustrated in detail in the Rinsche Patent No. 1,172,484. In the construction according to the Rinsche patent, the

tumbling of the register 'from adding position to ble of being done in Pasinski Patent No. 1,778,506,

and, furthermore, the tens transfer pawls for the actuator racks, for the units orders of both sections of the register or all sections of the register, in caseA there are more than two sections, are tripped by the tumbling of the register from its addingto its subtracting position, or reversely in the same way, as the transfer pawl for the units order rack of the machine of the Rinsche patent is tripped. 'Ihe mechanism which makes it possible to take mixed balances will now be described.

A plurality of hooks lll and 'ma (Fig. 2) are secured to shafts d and 49a, respectively, there being a hook foreach actuator rack of each seotion of the machine, the hooks being proportioned tov engage the actuator racks at predetermined times in total taking operators to prevent total taking in the associated registers.

The two sections of hooks 10 and llila are controlled independently of each other through the two negative total lock mechanisms in such a manner that when a mixed balance is carried as, for example, when an overdraft occurs in the left section of the machine and a positive total in the right section, the right section is allowed to zeroize while the left section is blocked and vice versa. In the event that an overdraft occurs in both sections of the machine and the operator is unaware of this condition the hooks 10 and lila of both sections engage their respective racks. Therefore during the rst totaling operation in which operation the add subtract lever I3 and the register frame l2 will be in addition position no printing or z-eroizing will occur, but during the second totaling operation in which the add subtract lever i3 and the register frame I2 will be in subtraction position, both sets of hooks will be released simultaneously and both sections will print true negative totals.

lConsidering first an overdraft in the left section of the machine. It will be recalled that under such .condition the three arm lever 33 is moved counterclockwise. This lever carries a stud 1| which is moved rearwardly with the lever 33 and upon clockwise movement thereof (Fig. 6) engages a cam 12 formed-on a lever 13 pivoted about stud 26 (Figs. 2 and 6). Lever 'I3 is normally urged counterclockwise as viewed in Fig.

2 and clockwise in Fig. 6 by a spring i6, but when an overdraft occurs it is moved by the stud 'Il against the action of spring 1B. Lever 73 carries a stud i6 upon its outer or forward end in position to engage under the forward end of a link 1l having an L-shaped slot at its forward end with a horizontal portion 'i8 anda vertical portion 19. For the right section of the machine similar parts are provided and designated by the same numerals but with the suilix a. The rear ends ofy links ll l'la are pivotally connectedito arms 8l and 8|i secured to a shaft 82 supported in the machine side frames extending across the machine parallel to shaftM. Secured to shaft 44 is a depending arm 83, the Ylower end of which carries a square stud 84 which projects into the L-shaped slot 78, 79. A similar arm'a is secured to the shaft section 6ta and has' a square stud 84a projecting into the L-shaped slot in the link lla. When the machine is in normal position hooks lll are held in disengaged position by springs 8l, which tend to rotate shaft d counterclockwise (Fig. 2) until the upper end of arm 83 engages the front edge of the keyboard plate 88, and stud 39 lies directly under the vertical portion 19 of the L-shaped slot.

Shaft 82 is actuated by the total key through an arm 9| connected by a link 92 to the downwardly extending arm 93 of the total key lever T (Fig. 2). Upon depression of the total key, shaft 82 is rocked counterclockwise and links 'll and lla are moved rearwardly. If the left section of the machine is in positive condition stud 16 will hold link l'l in upper position where square stud 84 lies within the horizontal portion 78 of the L- shaped slot. Accordingly when the total key is depressed, link ll is moved rearward but is moved idly on stud 86 and does notrock shaft 44 to move hooks l0 which therefore remain in normal or inoperative position so that the racks 4 are free for movement and total taking.

At this time, however, if the right section is in negative total condition the pin 16B will be lowered by the negative total lock mechanism and permit link lla to drop to place stud 8d in the vertical section 198 of the! L-shaped slot. De-

pression of the total key therefore will rotate shaft Ma through link 'l'lB and arm 83S to bring hooks ICIa into engagement with the racks of the right section to block those racks during the total taking operation for the left section of the register which has been assumed to be in positive condition. Of course if the condition of the two register sections were reversed the operations would be reversed and upon depression of the total key and a stroke of operation of the machine the racks in the. left section would be prevented from dropping during taking of the total in the right section. If, on the other hand, both register sections were in negative condition while the add subtract lever I3 and the register frame l2 were in addition position, both hooks l0 and llla would be rocked to effective position and neither set of racks would be permitted to move upon release and depression of total key T during' the operation of the machine.

Assuming again that the left section was in positive condition and the right section in negativecondition, after the positive section of the machine has been cleared during the first totaling operation at which time actuator racks of the. right section were held locked to prevent the right section from being zeroized, the negative total lock mechanism for the negative section of the machine will still be in negative position.

That is link 11a will be in lowered position and must be moved to inactive position otherwise the hooks would remain engaged to block movement of the actuator racks of the right section during the second totaling operation, exactly as they were during the iirst totaling operation. Provision must be made therefore to normalize or disable link 11 during the second totaling operation. 'I'he mechanism for this is as follows:

Referring to Fig. 2 it will be seen that subtraction control lever I3 is pivoted at 95 to the machine frame and carries a stud 96 which engages a forked end of a lever 91 secured to a shaft 98 supported by brackets carried by the machine side frames. Shaft carries two arms 99 positioned to engage studs I0I` carried by levers |02 journaled upon shaft 82. Levers |02 extend forwardly and carry at their ends laterally projecting studs |03 which underlie links 11 and 11. When arms |02 are rocked by movement of the subtraction control lever I3 from addition to subtraction position, studs |03 engage links 11 and 11a and raise them suiciently to bring the horizontal portions 18 and 18 of the L-shaped slots in operative position relatively to the studs 04 and 04B. Therefore, during the second total taking operation, which is a negative total taking operation in the present example, (Fig.,7), the hooks 10l of the right hand section will be free of the racks 4a of that section, and because the right hand register section pinions are in negative condition, a total taken from that section will be a true negative total. If the operator realizes that both sections of the machine are in negative condition he may immediately shift subtraction control lever I3 to subtract position and simultaneously take a true negative total of both sections of the register in one machine operation without first going through an idle positive totaling operation. The negative totals as well as the subtract items may be printed in red as is the customary practice to distinguish from positive totals and negative totals.

Operation The operation of the machine will be summarized in connection with Fig. 'l which illustrates one form of record sheet or work sheet which may be used in connection with a machine embodying the principles of the foregoing invention. In this form the sheet is divided into three columns, column 1 for amounts that are to be added, column 2 for amounts that are to be subtracted and column 3 for the totals whether they be positive or negative. Each column is of suirlcient width to take two independent entries and the machine is arranged so that it automatically is put in subtraction condition when the form reaches column 2. It will be understood that additional columns may be provided for other addition or subtraction entries if desired, a simple form being shown for convenience.

In the illustrated example, the-necessary keys of the two divisions of the keyboard are depressed to enter 555 articles in the left division and 5.55 in the right section of the register while the paper carriage is in column 1. The machine is then given a stroke or cycle of operation after which the paper carriage is automatically tabulated to column 2.- While the paper carriage is in column 2 position the proper keys are depressed in the two divisions of the keyboard to subtract 222 from 555 posted in the left register section and 7.77

from 5.55 posted in the right register section after which the machine is given a stroke of operation and the paper carriage is automatically tabulated to column 3. The total in the left register section is a positive amount but inasmuch as a larger amount was subtracted from a relatively smaller amount in the right register section the right register section is in negative condition thus resulting in a mixed balance, that is, a positive total, or balance, in the left section; and a negative total or balance in the right hand section. 'I'his condition will be indicated because the total in the registers being negative the total key will be locked against depression because of pawl 24 on the subtract pinion II of the highest order engaging arm 3| a and setting into motion the necessary mechanism as previously described to cause lever 52 to be rocked counterclockwise to bring its upper arm 53 immediately beneath stud 54. y

The operator then takes two spacing strokes to tumble the registers to add condition if not already there and to restore the racks to normal position.v He then releases the total key by manual operation of lever 60 which enables lever 52 to move clockwise to inoperative position by its spring 55. The total key is then depressed and the machine is given a stroke of operation. During this stroke of operation the positive totalV 333 is taken on the register which is in positive condition, that is, the left register section, the right register section is and remains locked against clearing or zeroizing by means of hooks 10a which have been rocked intoengagement with the racks I* by the mechanism set into motion by the negative total lock. This permits independent totalizing of eachof the two register sections without affecting the other register section.

In order to take a total from the right register section which is in negative condition, it is necessary to move the subtraction control lever I3 to subtract position and give the machine two spacing strokes. Movement of lever I3 to subtraction position disables hooks 10 of the right section racks after which the total key is depressed with the subtraction control lever I3 in subtract positionand the machine is given a stroke of operation to take a true negative total 2.22 in the right register section. During this operation the left register section is retained in its zero position.

It follows from the foregoing that although the different register sections are all carried in a single frame and are all simultaneously engaged with the actuator racks in positive or negative total taking relation the machine is capable of taking a mixed balance regardless of which register contains a positive total and which one a negative total. In other words, it is possible to accumulate two or more groups or listings simultaneously until the balance column is reached, after which a positive total can be taken from one section of the machine and a negative total can be taken from the other section of the machine, because of the automatic control of the racks depending upon the positive or negative condition of the register sections.

It will be apparent to those skilled in the art that minor changes may be made in the details of construction without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. In a calculating machine having a register divided into a plurality of sections, each capable of addition and subtraction, differential mechanism for entering amounts in said registers, a plurality of depressible keys for controlling the tive condition have been totaled.

2. In a calculating machinehaving a register divided into a plurality of sections each capable of addition and subtraction, diierential mechanisms for entering amounts in Said register, keys for controlling simultaneous entry of amounts in said register sections upon a single cycle of operation of said machine, a single total key, connections therefrom for causing a total to be taken from each of said register sections, locking devicesv controlled in accordance with the condition of said register sections and arranged to disable certain parts of said machine to prevent clearing of the register sections in predetermined condition duringa total taking operation, and means for preventing disabling by said locking devices to enable the taking of a total from said latter register sections after said register sections not in predetermined condition have been totaled.

3. In a calculating machine having a register divided into a plurality of sections each capable of addition and subtraction, differential mechanisms for entering amounts in said register, keys for controlling entry of amounts in said register. sections upon operation of said machine, a total key, connections therefrom for causing a total to be taken from each of said register sections, locking devices controlled in accordance with the condition of said register sections and arranged to disable certain parts of said differential mechanisms to prevent clearing of the register sections in predetermined condition during a total taking operation, and means for preventing disabling by said locking devices to enable the taking of a total from said latter register sections after said register sections not in predetermined condition have been totaled.

4. In a calculating machine having a register divided into a plurality of sections each capable of addition and subtraction, a plurality of depressible keys, diierential movable racks controlled by said keys for simultaneously entering amounts in said register sections upon a single cycle of operation of said machine, total taking control means, locking devices controlled in accordance with the condition of said register sections and arranged to block movement of certain of said racks during a totaling operation, but being ineffective as to other racks, and means for releasing said lockingdevices to enable the taking of totals from the register sections 'associated with said blocked racks after the register sections as.

a positive or a negative condition, said amount' determining diierential mechanism and said registering mechanism being divided into two sections operable independently of one another in aooasee the entering and accumulation of amounts whereby o ne section of said registering mechanism may`reach a negative condition while the other is in positive condition, total taking control means for causing a total to be takenl from said registering mechanism, said total taking control means f operating to cause an engagement between both of said vsections and said racks for a total taking operation and to normally release all of said racks, means operated by an element of said total taking control means when there is a negative total in one section of said registering mechanism to block the racks corresponding to said section during a total taking operation whereby when a positive total is` taken from the section that is positive the negative section is undisturbed, and means for releasing the blocked racks whereby a negativetotal may be subsequentlyv taken from the section that is negative.

pendently of one another in the entering and accumulation of amounts whereby one section of said registering mechanism may reach a negative condition while the other is in positive condition, total taking control means for causing a total to be taken from said registering mechanism, said total taking control means operating to cause an engagement between both of said sections and said racks for a total taking operation and to normally release all of said racks, means operating automatically when there isa negative total in one section to lock said total taking controlmeans, means controlled by said automatically operating means and actuated by said total taking control means to block the racks in the section that is negative during a total taking operation, means for releasing said total taking control means without releasing said lblocked racks whereby a total may be taken from the section that is positive, and means for then releasing said blocked racks and conditioning said machine for a subtraction type of engagement bevof addition and subtraction, depressible keys, differential mechanism controlled by said keys for simultaneously entering amounts in said register sections upon a single cycle of operation of said machine,'a subtract levei` for conditioning elements of the machine to cause it to perform subtraction, total taking control means, locking devices controlled in accordance with the condition of said register sections and arranged to block certain elements of .zs'aid machine during a totaling operation to prevent totaling in certain registers but being ineffective as to other registers, and means controlled by said subtract lever for disabling said locking devices' to permit the taking of totals from said blocked register sections after said other register sections have been totaled.

8. In a calculating machine having a register divided into a plurality of sections, each capable of addition and subtraction, depressible keys, differential mechanism controlled by said keys for simultaneously entering amounts in said register sections upon a single cycle of operation of said machine, a single total key, connections therefrom for causing a total to be taken from each of said register sections, negative total locks arranged to prevent operation of said total key when a register section is in negative condition, subtraction control means additional locking devices controlled by elements of said total locks and arranged to block certain elements of said machine during a totaling operation to prevent totaling of said register sections in negative condition, means for releasing said total key to permit totaling in said register sections in positive condition without aiecting said additional locking devices, and means controlled by said subtraction control means for preventing blocking by said additional locking devices to enable the taking of true negative totals from said negative register sections upon a. subsequent totaling operation after said positive register sections have been totaled.

9. A calculating machine adapted to be given cycles of operation, having ar amount determining differential mechanism upon whichtwo different amounts may be indexed at the same time, two registering mechanisms each of which is capable of addition and subtraction whereby either may reach a positive or a negative condition, means for conditioning certain elements of the machine to cause addition or subtraction in said registering mechanisms, means operating during a cycle of operation of the machine to cause two different amounts to be simultaneously entered in their respective registering mechanisms, total taking control means for causing totals to be taken from said registering mechanisms, said totaltaking control means being controlled by a manipulative means and being operable to cause a true negative total to be taken from either registering mechanism when said registering mechanism is negative, means operating automatically when there is a negative total in one of said registering mechanisms, to lock said manipulative means,

means for releasing said manipulative means t0 enable a total to be taken from the register that is in positive condition, means for preventing taking a. total from the registering mechanism that is negative-while a positive total is being taken, and means for then releasing said preventing means to enable the total to be taken from the registering. mechanism that isv in negative condition after the register in positive condition has been cleared. ROBERT L. MULLER. 

